1. Field
The present embodiments relate to a tunnel-type detecting element and a method of manufacturing the same.
2. Related Art
JP-A-2004-006589 described below discloses a tunnel-type magnetic detecting element. JP-A-2004-006589 discloses that an insulating barrier layer (referred to as ‘nonmagnetic spacer’ in JP-A-2004-006589) is formed of oxidized insulation materials including Al2O3, MgO, SiO2, HfO2 and SrTiO3 ([0192] of JP-A-2004-006589).
At least one of a first magnetic layer and a second magnetic layer is formed of materials having a body-centered cubic (bcc)-type crystal structure, a film surface thereof is oriented substantially parallel to (110) surfaces (claim 15 of JP-A-2004-006589).
Heusler alloy, which is a half metal, is used for the first magnetic layer or the second magnetic layer. As disclosed in [0015] of JP-A-2004-006589, it is possible to set theoretical resistance variation rate (ΔR/R) to infinity by using the half metal.
However, it was possible to actually obtain at most several tens % (ΔR/R). In the related art, it is difficult to get a sufficiently half metallic characteristic of Heusler alloy.
Since lattice matching does not occur in an interface between a Heusler alloy layer and the insulating barrier layer (a misfit ratio is high), a spin polarizability decreases in the vicinity of the interface. In addition, the insulating barrier layer formed of Al2O3; etc. is substantially an amorphous material and element diffusion occurs in the interface between the insulating barrier layer and the Heusler alloy layer, a film material of the insulating barrier layer or the Heusler alloy layer is deteriorated.
A specific method of improving a lattice matching property is not disclosed in JP-A-2004-006589.